Apparatus for removing plaster from plate glass surfacing tables



May 23, 1939. 1 `D, MCLEOD Er AL 2,159,631

` APPARATUS Fon nEnovING PLASTER FROM PLATE GLAss SURFAGIGUTABLES;

Filed Nov. 1,` 1955 3 Sheets-Sheet `l i a \\S f77-7b2' NE ra.

'KW /f/ May 23, 1939. J, D. MCLEOD n 2,159,631

APPARATUS FOR REIOVING PLASTER FROM PLATE GLASS SURFAGING TABLES FiledNOV. 1, 1935 3 Sheets-Shet 2 29793 sof' s /Vl/ENTOR 8V@ ,/CSW v May 23,1939. .1. D.'McLEoD Er Al.

APPARATUS-ROR` REHOVING PLASTER FROM IfLATE GLASS SURFACING TABLES.Filed NW 11 1935 `sA sheets-sheet s INA/5N To@ Halver/Q REVNOLo "Wec/oN/v o. MLon @Maw y- @ab HTTQQNE v6.

Patented May 23, 1939 UNITED `STATES PATENT OFFICE John D. McLeod,Oakmont, and Harry A. Reynolds, Ford City, Pa.,

assignors to Pittsburgh Plate Glass Company, a corporation of Penn-Sylvania Application November 1, 1935, Serial No. 47,896

Claims.

'I'he invention relates to brush apparatus for removing plaster from thetops of tables employed in the continuous surfacing of plate glass. Theglass is bedded in plaster of Paris, and after 5 the removal of theglass, it is necessary to cut away the old plaster before applying a newlayer. The objects of the present invention are to provide an improvedbrush construction for acting on the topsof the tables as they movetherebeneath along their tracks, which is cheap', with low replacementcost for the parts worn away in service, which acts very eciently to cutaway the plaster, and which does not cut away the tops of the tablesrapidly. One embodiment of the invention is illustrated in theaccompanying drawings, wherein:

Figure 1 is a partial vertical section through the apparatus. Fig. 2 isa plan View of the support- `ing framework or spider. Figs. 3 and 4 aredetail views of one of the brush holder plates, Fig. 3 being a plan Viewand Fig. 4 a section on the line IV--IV of Fig. 3. Figs. 5 and 6 aredetail views of the other brush holder plate, Fig. 5 being a plan viewand Fig. 6 a section on the line VI--VI of Fig. 5. And Figs. 7 and8 aredetail views of one of the clamping blocks, Fig. '7 being a sideelevation, and Fig. 8 a plan view.

The framework or spider shown in Fig. 2 comprises four arms 9, 9, 9, 9,each made up of a pair of angles Ill, I0, such angles being riveted tothe y rectangular plate I I. Secured at the center of the spider is ablock I Ia, in which is keyed the shaft I2 by means of which the spideris rotated` The block I I is held against downward movement with respectto the shaft by means of the keeper plate I3 secured to the end of theshaft by means of the stud bolt I4. The shaft I2 is driven from anelectric motor (not shown) which operates through suitable reducinggearing in the casing I5, the casing and motor being carried upon thedeck I6 bolted to the under side of the I-beams I1.

A runner carrying the abrading means is carried at the end of. each ofthe arms of the spider, the construction being shown in Fig. 1. The oth-,45 er runners are similar to that shown in this figure, so that theillustration and description of one runner will be a sucient disclosureof all. At the end of the runneris a block made up of two parts I8 and I9, which carries the shaft 2E! of the runner. The part I8 of the blocklies between the pair of angles I0, I0 and is secured rigidly thereto bymeans of three bolts 20a. The part I9 of the block is secured to thepart I8 by means of pairs of bolts 2l, a bushing 22 for the shaft 20being clamped `between the parts of the block and further securedagainst movement by means of the set screw 23.

In order to adjust the Vertical position of the. runner, the shaft 20 iscarried by the lever arm 24 pivoted at 25 between the pair of lugs 26 onthe block I8, the other end of the lever resting upon a pin 21 carriedby the bar 28,` such bar being secured at its lower end to the blockmember I9'. This bar is provided with a plurality of holes 29, asillustrated, so that the shaft 2l) and the runner carried thereby may beadjusted down as the abrading elements wear away. In order to secure theupper end of the shaft 20 to the'lever arm 24, clamping studs 3l! aremounted in the sides of the arm with their ends fitting into suitablerecesses in the sides of the shaft.

The construction of the runner or support for the abrading elements willbe seen by reference to Figs. 3 to 6 in connection with Fig. 1. The bodyof this runner or support consists of a pair of opposing plates 3l and32 clamped in the position shown by means of the bolts 33 which havetheir heads welded to the lower plate 32. The upper plate 3| is providedwith a collar 34 and this collar is secured to a flange 35 on the lowerend of the shaft 29 by means of the four bolts 36. The clamping blockswhich carry the abrading elements each consists of three plates 31, 31and 38 (Fig. 8) secured together by means of the bolts 39. Perforations40 are provided in the opposing faces of the plates, as indicated inFig. 8 and inv these openings or perforations are mounted the abradingelements 44. These abrading elements consist of sections 4I of wirecable made up of strands of wire twisted together. The diameter of thiscable is preferably about 9%; of an inch, but other sizes may be used ifdesired. Old worn out cable will serve just as well for this purpose asnew cable, so that the cost of renewing the abrading elements isrelatively small.

The abrading action of elements of this kind has been found to be verysatisfactory. The metal cable has about the right degree of hardness tocut the plaster without injury to the tables, and the sub-division ofthe elements, due to the plurality of strands which go to make up eachsection of the cable, give a plurality of cutting points which act veryeiectively to cut through the layer of plaster upon the tables as theyare moved beneath the device. As the cable wears away, the shaft 2D,supported upon. the arm 24, is adjusted downwardly from time to time sothat a large portion of the cable may be used before it is discarded.After the abrading sections have been worn down relatively close to thelower plate 32, the clamping blocks may be released from between theplates 3l and 32 and turned upside down, thus permitting most of eachsection to be utilized. In practice, the spiders are supported so thatthey may be shifted readily into and out of position and whenreplacement is required, little time need belo'st in removing the spiderand runners carried thereby and replacing it by another spider.

The plates 3l and 32 are provided with sets of perforations 42 and 43which are of less dimension than the clamping members 31, 3'!l and3$ sothat when the clamping blocks are positioned' between the plates, theirmargins are engagedl thereby and clamped when the'V nuts on the bolts 33are tightened. The perforations 42l and'43 are of such size that theywill receive the sets of cable sections 4 I What we claim is:

1. Apparatus for cleaning plaster from plate glass surfacing tablesmounted for movement along a track, said apparatus comprising a supportmounted for rotation about a vertical axis and consisting of a pair ofopposing perforated clamping plates lying in horizontal planes, clampslying between the plates at said perforations and havingverticalopenings therethrough, means. for releasably securing the platestogether with the clamps held therebetween, ahrading members extendingvertically through the perforationsin-the plates and the openings in theclamps,V said abrading members being held against vertical movementtherethrough by said clamps, and means for adjusting the supportdownwardly as said members are worn away.

2. Apparatus for cleaningplaster from plate glass surfacing tablesmounted for movement along a track, said apparatus comprising a spiderhaving radial arms,y and rotatable about a vertical axis, a block at theend of each arm, having a vertical opening therethrough', a shaftextending through eachopening, means for securing the shafts in aplurality of positions of vertical adjustment and holding them againstrotation, a support carried by each shaft consistingl of a pair ofopposing perforatedclamping plates lying in horizontal planes',4 clampslying between.. each pair of plates and havingvertical openings there--through, means releasably securing the plates together with the clampsheld. therebetween, and abrading members extending vertically throughthe perforations in the platesand the openings in the clamps, saidabrading members being held against vertical movement therethrough bysaid clamps.

3. In combination in apparatus adapted for cleaning plaster from plateglass surfacing tables,

an abrading runner comprising a vertical spindle engaging driving means,a support secure-d to the lower extremity of the spindle consisting of apair of opposing perforated clamping plates lying in horizontal planes,means releasably securing the plates together, a plurality of clampingblocks providedwith vertical openings therethrough positioned betweenthe clamping plates at said perforations, flexible abrading elementsextending vertically through the openings in the clamping blocks,projecting a substantial distance from eachface of said clamping blocksand held centrally against vertical movement by the clamping blocks, andmeans for adjusting the abrading elements downwardly as they are wornaway.

In combination in apparatus 'adapted for cleaning plaster from plateglass surfacing tables, an abrading runner comprising a vertical spindleengaging driving means, a support releasably secured to the lowerextremity of the spindle consisting of apair of opposing perforatedclamping plates lying in horizontal planes, means releasablysecuringsaid platesin spaced relation, a plurality of invertibleclamping blocks provided with vertical o-penings therethrough positionedbetween the clamping plates at said perforations, said clamping blocksbeing of greater dimensions than the perforations. in the clampingplates, and iiexible abradingy elements extending vertically through theopenings in the clamping blocks, projecting a substantial distance fromeach face of the clamping blocks and held centrally against verticalmovement by the clamping blocks, the invertibility of which permits theupper portion of the abrading members to be brought into operativeposition when the lower portionthereof has been worn away.

5. In anapparatus for cleaning plaster from` plate glass surfacingtables mounted for movement along a track, a unit carrier having meanssupporting it rotatably about a vertical axis,` a pair of opposedpla-tes disposed substantially horizontally and having registeringopenings extending therethrough, clamping jaws disposed between saidplates and traversing the registering openings therein, means forremovably securing said plates rigidly in their opposed relation uponopposite side-s of the clamping jaws carried therebetween, abradingmembers disposed between the clamp-ing jaws and extending in oppositedirections through the registering openings in the plates above andbelow the latter, means for se curing the clamping jaws rigidly upon theabrading members, and means for varying the elevation of the assembledplates and clamping jaws.

JOHN D. MCLEOD. HARRY A. REYNOLDS.

